NSF: Rocky Mountain wildflower season lengthens by more than a month

A 39-year study of wildflower blooms in a Colorado Rocky Mountain meadow shows that more than two-thirds of alpine flowers have changed their blooming patterns in response to climate change. Not only are half the flowers beginning to bloom weeks earlier, but more than a third are reaching their peak blooms earlier, and others are producing their last blooms later in the year. The blooming season, which used to run from late May through early September, now lasts from late April to late September, according to University of Maryland ecologist David Inouye.

The wildflower records, made up of more than two million blooms, suggest that flowering plants' responses to climate change are more complex than previously believed, with different species responding in unexpected ways. The combinations of flowering species that bloom together are changing, too, with potential effects on insects and birds.